U.S. patent application number 12/545871 was filed with the patent office on 2010-12-23 for touch screen and touch module.
This patent application is currently assigned to SONIX TECHNOLOGY CO., LTD.. Invention is credited to Chi-Feng Lee, Pei-Hui Tung.
Application Number | 20100321309 12/545871 |
Document ID | / |
Family ID | 43353876 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100321309 |
Kind Code |
A1 |
Lee; Chi-Feng ; et
al. |
December 23, 2010 |
TOUCH SCREEN AND TOUCH MODULE
Abstract
A touch screen including a display, at least two touch units and
a control unit is provided. The display has a displaying surface.
The touch units are disposed beside the displaying surface. Each of
the touch units includes a light source and an image sensor. The
light source is adapted to emit a light beam toward a sensible
space in front of the displaying surface. The image sensor is
adapted to capture the bright spot in the sensible space, and
generate an image signal. The control unit is electrically
connected to the light sources and the image sensors. The control
unit is adapted to receive the image signals from the image
sensors, and determine the position of the bright spot relative to
the displaying surface according to the image signals. A touch
module and a control method are also provided.
Inventors: |
Lee; Chi-Feng; (Hsinchu
County, TW) ; Tung; Pei-Hui; (Hsinchu City,
TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100, ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Assignee: |
SONIX TECHNOLOGY CO., LTD.
Hsinchu
TW
|
Family ID: |
43353876 |
Appl. No.: |
12/545871 |
Filed: |
August 24, 2009 |
Current U.S.
Class: |
345/173 |
Current CPC
Class: |
G06F 3/0421
20130101 |
Class at
Publication: |
345/173 |
International
Class: |
G06F 3/041 20060101
G06F003/041 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 22, 2009 |
TW |
98120875 |
Claims
1. A touch module, adapted to a display for making the display have
a touch function, the display having a displaying surface, the
touch module comprising: a first image sensor disposed at a first
position beside the displaying surface; a second image sensor
disposed at a second position beside the displaying surface; and a
control unit electrically connected to the first image sensor and
the second image sensor, wherein when at least one touch object
enters a sensing space in front of the displaying surface, the
first image sensor and the second image sensor sense a light beam
reflected by the at least one touch object, and the control unit is
adapted to determine a position of the at least one touch object
relative to the displaying surface according to the light beam
reflected by the at least one touch object and sensed by the first
image sensor and the second image sensor.
2. The touch module as claimed in claim 1, further comprising at
least one light source disposed beside the displaying surface and
adapted to emit the light beam entering the sensing space.
3. The touch module as claimed in claim 2, wherein the at least one
light source comprises a first light source and a second light
source respectively disposed at a third position and a fourth
position beside the displaying surface, the control unit is adapted
to continuously control the first light source and the second light
source in a plurality of continuous unit times, each of the unit
times comprises a first sub-unit time and a second sub-unit time,
the control unit is adapted to control the first light source to
stay at an ON state and the second light source to stay at an OFF
state in the first sub-unit time, and the control unit is adapted
to control the first light source to stay at the OFF state and the
second light source to stay at the ON state in the second sub-unit
time.
4. The touch module as claimed in claim 3, wherein the control unit
is adapted to control the first image sensor to stay at the ON
state and the second image sensor to stay at the OFF state in the
first sub-unit time, and the control unit is adapted to control the
first image sensor to stay at the OFF state and the second image
sensor to stay at the ON state in the second sub-unit time.
5. The touch module as claimed in claim 3, wherein each of the unit
times further comprises a third sub-unit time, the control unit is
adapted to control the first light source and the second light
source to stay at the OFF state in the third sub-unit time, the
control unit is adapted to subtract an image brightness sensed by
the first image sensor in the third sub-unit time of each of the
unit times from an image brightness sensed by the first image
sensor in the first sub-unit time of the corresponding unit time to
obtain a first touch image, the control unit is adapted to subtract
an image brightness sensed by the second image sensor in the third
sub-unit time of each of the unit times from an image brightness
sensed by the second image sensor in the second sub-unit time of
the corresponding unit time to obtain a second touch image, and the
control unit determines the position of the at least one touch
object relative to the displaying surface according to the first
touch image and the second touch image.
6. The touch module as claimed in claim 3, wherein the third
position and the fourth position are respectively located at two
neighboring corners of the displaying surface.
7. The touch module as claimed in claim 6, wherein the first
position and the third position are respectively located beside a
same corner of the displaying surface, and the second position and
the fourth position are respectively located beside a same corner
of the displaying surface.
8. The touch module as claimed in claim 3, further comprising a
third image sensor and a fourth image sensor respectively disposed
at a fifth position and a sixth position beside the displaying
surface, and sensing surfaces of the third image sensor and the
fourth image sensor facing to the sensing space, wherein the at
least one light source further comprises a third light source and a
fourth light source respectively disposed at a seventh position and
an eighth position beside the displaying surface, each of the unit
times further comprises a fourth sub-unit time and a fifth sub-unit
time, the control unit is adapted to control the third light source
and the fourth light source to stay at the OFF state in the first
sub-unit time, the control unit is adapted to control the third
light source and the fourth light source to stay at the OFF state
in the second sub-unit time, the control unit is adapted to control
the third light source to stay at the ON state and the first light
source, the second light source, and the fourth light source to
stay at the OFF state in the fourth sub-unit time, and the control
unit is adapted to control the fourth light source to stay at the
ON state and the first light source, the second light source, and
the third light source to stay at the OFF state in the fifth
sub-unit time.
9. The touch module as claimed in claim 8, wherein the at least one
touch object is two touch objects, when the touch objects are
simultaneously located in the sensing space in at least one of the
unit times, the touch images sensed by the first image sensor, the
second image sensor, the third image sensor, and the fourth image
sensor each have at least one reflex point, and the touch images
sensed by at least two of the first image sensor, the second image
sensor, the third image sensor, and the fourth image sensor each
have two reflex points in the at least one of the unit times, and
the control unit is adapted to compare positions of the reflex
points in the touch images to eliminate the positions of the touch
objects relative to the displaying surface which do not exist and
determine the positions of the touch objects relative to the
displaying surface.
10. The touch module as claimed in claim 3, wherein the first image
sensor and the second image sensor are maintained at the ON state
all the time in each of the unit times.
11. The touch module as claimed in claim 1, wherein the first
position and the second position are respectively located at two
neighboring corners of the displaying surface.
12. The touch module as claimed in claim 1, further comprising at
least one absorbing bar or at least one light-turning bar disposed
on at least one edge of the displaying surface, wherein the at
least one light-turning bar is adapted to reflect the light beam to
a direction away from the displaying surface.
13. A touch module, adapted to a display, for making the display
have a touch function, the display having a displaying surface, the
touch module comprising: a first image sensor disposed at a first
position beside the displaying surface; a second image sensor
disposed at a second position beside the displaying surface; a
first light source disposed at a third position beside the
displaying surface and adapted to emit a light beam entering a
sensing space in front of the displaying surface; a second light
source disposed at a fourth position beside the displaying surface
and adapted to emit a light beam entering the sensing space; and a
control unit electrically connected to the first light source, the
second light source, the first image sensor, and the second image
sensor, wherein the control unit is adapted to continuously control
the first light source and the second light source in a plurality
of continuous unit times, each of the unit times comprises a first
sub-unit time and a second sub-unit time, the control unit is
adapted to control the first light source to stay at an ON state
and the second light source to stay at an OFF state in the first
sub-unit time, the control unit is adapted to control the first
light source to stay at the OFF state and the second light source
to stay at the ON state in the second sub-unit time, when at least
one touch object enters the sensing space, the first image sensor
and the second image sensor sense images of the at least one touch
object, and the control unit is adapted to determine a position of
the at least one touch object relative to the displaying surface
according to the images sensed by the first image sensor and the
second image sensor.
14. The touch module as claimed in claim 13, wherein the control
unit is adapted to control the first image sensor to stay at the ON
state and the second image sensor to stay at the OFF state in the
first sub-unit time, and the control unit is adapted to control the
first image sensor to stay at the OFF state and the second image
sensor to stay at the ON state in the second sub-unit time.
15. The touch module as claimed in claim 13, wherein each of the
unit times further comprises a third sub-unit time, the control
unit is adapted to control the first light source and the second
light source to stay at the OFF state in the third sub-unit time,
the control unit is adapted to subtract an image brightness sensed
by the first image sensor in the third sub-unit time of each of the
unit times from an image brightness sensed by the first image
sensor in the first sub-unit time of the corresponding unit time to
obtain a first touch image, the control unit is adapted to subtract
an image brightness sensed by the second image sensor in the third
sub-unit time of each of the unit times from an image brightness
sensed by the second image sensor in the second sub-unit time of
the corresponding unit time to obtain a second touch image, and the
control unit determines the position of the at least one touch
object relative to the display according to the first touch image
and the second touch image.
16. The touch module as claimed in claim 13, wherein the third
position and the fourth position are respectively located at two
neighboring corners of the displaying surface.
17. The touch module as claimed in claim 16, wherein the first
position and the third position are respectively located beside a
same corner of the displaying surface, and the second position and
the fourth position are respectively located beside a same corner
of the displaying surface.
18. The touch module as claimed in claim 13, wherein the first
image sensor and the second image sensor are maintained at the ON
state all the time in each of the unit times.
19. A touch screen, comprising: a display having a displaying
surface; at least two touch units disposed beside the displaying
surface, and each of the touch units comprising: a light source
disposed beside the displaying surface and adapted to emit a light
beam entering a sensing space in front of the displaying surface;
and an image sensor disposed beside the displaying surface, and a
sensing surfaces of the image sensor facing to the sensing space,
wherein the image sensor is adapted to capture a bright spot in the
sensing space and generate an image signal; and a control unit
electrically connected to the light sources and the image sensors,
wherein the control unit is adapted to receive the image signals
from the image sensors and determine a position of the bright spot
relative to the displaying surface according to the image
signals.
20. The touch screen as claimed in claim 19, wherein the control
unit is adapted to drive the light sources of the touch units by
turns.
21. The touch screen as claimed in claim 20, wherein after driving
the light source of one of the touch units and before driving the
light source of another one of the touch units, the control unit is
adapted to maintain the light sources of the touch units at an OFF
state, the control unit is adapted to subtract an image brightness
sensed by the image sensor of each of the touch units while the
light source of the same touch unit is maintained at the OFF state
from an image brightness sensed by the same image sensor thereof
while the same light source is driven to obtain a touch image, and
the control unit determines the position of the bright spot
relative to the displaying surface according to the touch
image.
22. The touch screen as claimed in claim 19, wherein the control
unit comprises: at least two signal processors electrically
connected to the image sensors of the touch units respectively,
wherein each of the signal processors is adapted to determine the
position of the bright spot according to the image sensed by the
corresponding image sensor and generate a one-dimensional
coordinate signal; and a back-end processor electrically connected
to the signal processors, wherein the back-end processor is adapted
to receive the one-dimensional coordinate signals generated by the
signal processors and determine the position of the bright spot
relative to the displaying surface according to the one-dimensional
coordinate signals.
23. The touch screen as claimed in claim 19, wherein the control
unit is adapted to control the image sensor to repeatedly capture
the bright spot in the sensing space and determine a position
change of the bright spot according thereto.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Taiwan
application serial no. 98120875, filed on Jun. 22, 2009. The
entirety of the above-mentioned patent application is hereby
incorporated by reference herein and made a part of
specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a touch module
and a touch screen, and more particularly, to an optical touch
module and an optical touch screen.
[0004] 2. Description of Related Art
[0005] With the development of optoelectronic technology, it can
not satisfy a user's requirement to control the operating platform
and objects in the screen by using a mouse. Accordingly, an
interface more humanistic than the mouse is gradually developed. In
these humanistic interfaces, the touch method by using fingers is
closest to human experience in the daily life. Accordingly, elders
and children may not use the mouse, but they can touch with fingers
easily. It has been partially proved that the touch screen is
adapted in ATM. A plurality of methods in which touch interfaces
are realized are provided in related arts. For example, a touch
film is adhered to the panel of the liquid crystal display (LCD) in
the related art, so that a resistive touch screen or a capacitive
touch screen is provided. Alternatively, a tiny touch device may be
integrated in the liquid crystal panel in another related art.
However, the touch film adhered to the panel and the tiny touch
device integrated in the panel both affect light transmittance of
the LCDs. Accordingly, optical quality of the LCDs is reduced.
Moreover, the position of the finger or the touch pen relative to
the screen is determined by using optically sensing method in
another related art. However, in the above-described related art,
the position of the finger is determined by capturing dark spots
which are formed due to the finger or the touch pen screening light
beams. However, in order to exactly identify the dark spots and
reduce failure rate, a good and uniform back light source is
required, so that the dark spots are more obvious than the back
light source. The back light source is provided by adhering
reflecting bars and light emitting bars to edges of the displaying
surface of the screen, but it may simultaneously increase
complexity and cost of assembly. Furthermore, it is easily affected
by environment light beams to capture the dark spots. Specifically,
when the environment light beams illuminate the finger or the touch
pen and are reflected to image sensors, the dark spots are not
identified.
SUMMARY OF THE INVENTION
[0006] An embodiment of the present invention provides a touch
module of which a structure is simple and has low failure rate.
[0007] An embodiment of the present invention provides a touch
screen having low failure rate.
[0008] An embodiment of the present invention provides a touch
module adapted for a display, so that the display has a touch
function. The display has a displaying surface, and the touch
module includes a first image sensor, a second image sensor, and a
control unit. The first image sensor is disposed at a first
position beside the displaying surface. The second image sensor is
disposed at a second position beside the displaying surface. The
control unit is electrically connected to a light source, the first
image sensor, and the second image sensor. When at least one touch
object enters a sensing space in front of the displaying surface,
the first image sensor and the second image sensor sense a light
beam reflected by the at least one touch object, and the control
unit is adapted to determine a position of the touch object
relative to the displaying surface according to the light beam
reflected by the touch object and sensed by the first image sensor
and the second image sensor.
[0009] In an embodiment of the present invention, the touch module
further includes at least one light source disposed beside the
displaying surface and adapted to emit the light beam entering the
sensing space.
[0010] In an embodiment of the present invention, the
above-described light source includes a first light source and a
second light source which are respectively disposed at a third
position and a fourth position beside the displaying surface. The
control unit is adapted to continuously control the first light
source and the second light source in a plurality of continuous
unit times. Each of the unit times includes a first sub-unit time
and a second sub-unit time. The control unit is adapted to control
the first light source to stay at an ON state and the second light
source to stay at an OFF state in the first sub-unit time. The
control unit is adapted to control the first light source to stay
at the OFF state and the second light source to stay at the ON
state in the second sub-unit time.
[0011] In an embodiment of the present invention, the control unit
is adapted to control the first image sensor to stay at the ON
state and the second image sensor to stay at the OFF state in the
first sub-unit time. The control unit is adapted to control the
first image sensor to stay at the OFF state and the second image
sensor to stay at the ON state in the second sub-unit time.
[0012] In an embodiment of the present invention, each of the unit
times further includes a third sub-unit time. The control unit is
adapted to control the first light source and the second light
source to stay at the OFF state in the third sub-unit time. The
control unit is adapted to subtract an image brightness sensed by
the first image sensor in the third sub-unit time of each of the
unit times from an image brightness sensed by the first image
sensor in the first sub-unit time of the corresponding unit time to
obtain a first touch image. The control unit is adapted to subtract
an image brightness sensed by the second image sensor in the third
sub-unit time of each of the unit times from an image brightness
sensed by the second image sensor in the second sub-unit time of
the corresponding unit time to obtain a second touch image. The
control unit determines the position of the touch object relative
to the displaying surface according to the first touch image and
the second touch image.
[0013] In an embodiment of the present invention, the third
position and the fourth position are respectively located at two
neighboring corners of the displaying surface. The first position
and the third position are respectively located beside a same
corner of the displaying surface, and the second position and the
fourth position are respectively located beside a same corner of
the displaying surface.
[0014] In an embodiment of the present invention, the touch module
further includes a third image sensor and a fourth image sensor
which are respectively disposed at a fifth position and a sixth
position beside the displaying surface. Sensing surfaces of the
third image sensor and the fourth image sensor face to the sensing
space. The light source further includes a third light source and a
fourth light source which are respectively disposed at a seventh
position and an eighth position beside the displaying surface. Each
of the unit times includes a fourth sub-unit time and a fifth
sub-unit time. The control unit is adapted to control the third
light source and the fourth light source to stay at the OFF state
in the first sub-unit time. The control unit is adapted to control
the third light source and the fourth light source to stay at the
OFF state in the second sub-unit time. The control unit is adapted
to control the third light source to stay at the ON state and the
first light source, the second light source, and the fourth light
source to stay at the OFF state in the fourth sub-unit time. The
control unit is adapted to control the fourth light source to stay
at the ON state and the first light source, the second light
source, and the third light source to stay at the OFF state in the
fifth sub-unit time.
[0015] In an embodiment of the present invention, the number of the
touch objects, for example, is two. When the touch objects are
simultaneously located in the sensing space in at least one of the
unit times, the touch images sensed by the first image sensor, the
second image sensor, the third image sensor, and the fourth image
sensor each have at least one reflex point, and the touch images
sensed by at least two of the first image sensor, the second image
sensor, the third image sensor, and the fourth image sensor each
have two reflex points in the unit times. The control unit is
adapted to compare positions of the reflex points in the touch
images to eliminate the positions of the touch objects relative to
the displaying surface which do not exist and determine the
positions of the touch objects relative to the displaying
surface.
[0016] In an embodiment of the present invention, the first image
sensor and the second image sensor are maintained at the ON state
all the time in each of the unit times.
[0017] In an embodiment of the present invention, the first
position and the second position are respectively located at two
neighboring corners of the displaying surface.
[0018] In an embodiment of the present invention, the touch module
further includes at least one absorbing bar or at least one
light-turning bar which is disposed on at least one edge of the
displaying surface, wherein the light-turning bar is adapted to
reflect the light beam to a direction away from the displaying
surface.
[0019] Another embodiment of the present invention provides a touch
module adapted for a display, so that the display has a touch
function. The display has a displaying surface, and the touch
module includes a first light source, a second light source, a
first image sensor, a second image sensor, and a control unit. The
first image sensor is disposed at a first position beside the
displaying surface. The second image sensor is disposed at a second
position beside the displaying surface. The first light source is
disposed at a third position beside the displaying surface and
adapted to emit a light beam entering a sensing space in front of
the displaying surface. The second light source is disposed at a
fourth position beside the displaying surface and adapted to emit a
light beam entering the sensing space. The control unit is
electrically connected to the first light source, the second light
source, the first image sensor, and the second image sensor. The
control unit is adapted to continuously control the first light
source and the second light source in a plurality of continuous
unit times. Each of the unit times includes a first sub-unit time
and a second sub-unit time. The control unit is adapted to control
the first light source to stay at an ON state and the second light
source to stay at an OFF state in the first sub-unit time. The
control unit is adapted to control the first light source to stay
at the OFF state and the second light source to stay at the ON
state in the second sub-unit time. When at least one touch object
enters the sensing space, the first image sensor and the second
image sensor sense an image of the at least one touch object, and
the control unit is adapted to determine a position of the at least
one touch object relative to the displaying surface according to
the image sensed by the first image sensor and the second image
sensor.
[0020] Another embodiment of the present invention provides a touch
screen which includes a display, at least two touch units, and a
control unit. The display has a displaying surface. The touch units
are disposed beside the displaying surface, and each of the touch
units includes a light source and an image sensor. The light source
are disposed beside the displaying surface and adapted to emit a
light beam entering a sensing space in front of the displaying
surface. The image sensor is disposed beside the displaying
surface, and a sensing surface of the image sensor faces to the
sensing space, wherein the image sensor is adapted to capture a
bright spot in the sensing space and generate an image signal. The
control unit is electrically connected to the light sources and the
image sensors, wherein the control unit is adapted to receive the
image signals from the image sensors and determine a position of
the bright spot relative to the displaying surface according to the
image signals.
[0021] In an embodiment of the present invention, the control unit
is adapted to drive the light sources of the touch units by
turns.
[0022] In an embodiment of the present invention, after driving the
light source of one of the touch units and before driving the light
source of another one of the touch units, the control unit is
adapted to maintain the light sources of the touch units at an OFF
state. The control unit is adapted to subtract an image brightness
sensed by the image sensor of each of the touch units while the
light source of the same touch unit is maintained at the OFF state
from an image brightness sensed by the same image sensor thereof
while the same light source is driven to obtain a touch image, and
the control unit determines the position of the bright spot
relative to the displaying surface according to the touch
image.
[0023] In an embodiment of the present invention, the control unit
includes at least two signal processors and a back-end processor.
The signal processors are electrically connected to the image
sensors of the touch units respectively, wherein each of the signal
processors is adapted to determine the position of the bright spot
according to the image sensed by the corresponding image sensor and
generate a one-dimensional coordinate signal. The back-end
processor is electrically connected to the signal processors,
wherein the back-end processor is adapted to receive the
one-dimensional coordinate signals generated by the signal
processors and determine the position of the bright spot relative
to the displaying surface according to the one-dimensional
coordinate signals.
[0024] In an embodiment of the present invention, the control unit
is adapted to control the image sensor to repeatedly capture the
bright spot in the sensing space and determine a position change of
the bright spot according thereto.
[0025] In the touch screen and the touch module in the embodiments
of the present invention, the image sensor is used to capture the
bright spot, i.e. the light beam reflected by the touch object.
Compared with the touch module in which capturing a dark spot, i.e.
a light shading spot, is adopted, and a good back light source is
formed by disposing reflecting bars and light emitting bars on
edges of the displaying surface, the structures of the touch screen
and the touch module in the embodiments of the present invention
are simpler. Accordingly, it can reduce cost of the touch screen
and the touch module, and the touch screen is beautiful.
[0026] Moreover, the light sources are controlled to stay at the ON
state by turns in the touch module and the touch screen in the
embodiments of the present invention. Accordingly, it is avoided
that the image sensors are interfered with light beams emitted by
unnecessary light sources. Therefore, the touch module and the
touch screen in the embodiments of the present invention have low
failure rate.
[0027] To make the aforementioned and other features and advantages
of the present invention more comprehensible, several embodiments
accompanied with figures are described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0029] FIG. 1A is a front view of a touch screen and an operating
platform according to an embodiment of the present invention.
[0030] FIG. 1B is a schematic cross-sectional view of the touch
screen in FIG. 1A along line I-I.
[0031] FIG. 1C is an enlarged view of touch units in FIG. 1A.
[0032] FIG. 2A is a driving period distribution of the control unit
in FIG. 1A.
[0033] FIG. 2B is a flowchart of a control method of the touch
module shown in FIG. 1A.
[0034] FIG. 3A is a front view of a touch screen and an operating
platform according to another embodiment of the present
invention.
[0035] FIG. 3B is a schematic cross-sectional view of the touch
screen in FIG. 3A along line II-II.
[0036] FIG. 4A is a driving period distribution of the control unit
in FIG. 3A.
[0037] FIG. 4B is a flowchart of a control method of the touch
module shown in FIG. 3A.
[0038] FIG. 5A is a front view of a touch screen and an operating
platform according to another embodiment of the present
invention.
[0039] FIG. 5B is a schematic cross-sectional view of the touch
screen in FIG. 5A along line III-III.
[0040] FIG. 5C is another view of the touch screen in FIG. 5B.
[0041] FIG. 6A is a front view of a touch screen and an operating
platform according to another embodiment of the present
invention.
[0042] FIG. 6B is a schematic cross-sectional view of the touch
screen in FIG. 6A along line IV-IV.
[0043] FIG. 7 is a front view of a touch screen and an operating
platform according to another embodiment of the present
invention.
[0044] FIG. 8A is a driving period distribution of the control unit
in FIG. 7.
[0045] FIG. 8B is a flowchart of a control method of the touch
module shown in FIG. 7.
[0046] FIG. 9 is a front view of a touch screen and an operating
platform according to another embodiment of the present
invention.
DESCRIPTION OF EMBODIMENTS
[0047] FIG. 1A is a front view of a touch screen and an operating
platform according to an embodiment of the present invention. FIG.
1B is a schematic cross-sectional view of the touch screen in FIG.
1A along line I-I. FIG. 1C is an enlarged view of touch units in
FIG. 1A. Referring to FIG. 1A, FIG. 1B, and FIG. 1C, the touch
screen 100 of the present embodiment includes a display 200, at
least two touch units 310, and a control unit 320. In the present
embodiment, the touch units 310 and control unit 320 may compose of
a touch module 300. The display 200 has a displaying surface 210.
In the present embodiment, the touch units 310 is disposed beside
the displaying surface 210, and each of the touch units 310
includes at least one light source 312 and an image sensor 314. In
FIG. 1A, the number of the light sources 312, for example, is two.
In other words, in the present embodiment, the touch module 300
includes at least one light source 312, a first image sensor 314a,
a second image sensor 314b, and a control unit 320.
[0048] The light source 312 are disposed beside the displaying
surface 210 and adapted to emit a light beam 313 entering a sensing
space S in front of the displaying surface 210. The image sensor
314 is disposed beside the displaying surface 210. In the present
embodiment, a sensing surface 315 of the image sensor 314 faces to
the sensing space S. In the present embodiment, a traveling
direction of the light beam 313 is substantially parallel to the
displaying surface 210, and the sensing space S is defined as a
space in front of the displaying surface 210 in which the light
beam 313 travels and is sensed by the image sensor 314. A position
and a scope thereof, for example, is shown in a dotted line in FIG.
1A and FIG. 1B. Moreover, in the present embodiment, the first
image sensor 314a is disposed at a first position beside the
displaying surface 210 as shown in FIG. 1A, and the second image
sensor 314b is disposed at a second position beside the displaying
surface 210 as shown in FIG. 1A.
[0049] In the present embodiment, the image sensor 314 is adapted
to capture a bright spot in the sensing space S and generate an
image signal. Specifically, when at least one touch object 50, i.e.
a finger in FIG. 1A, enters the sensing space S, the first image
sensor 314a and the second image sensor 314b sense the light beam
313 reflected by the touch object 50, and an image of the touch
object 50 imaged on the image sensor 314 is a bright spot. In the
present embodiment, an imaging device 316 is disposed in front of
the image sensor 314 to image the light beam 313 reflected by the
touch object 50 on the image sensor 314, wherein the imaging device
316, for example, is a lens or a pin hole.
[0050] In the present embodiment, the control unit 320 is
electrically connected to the light sources 312 and the image
sensors 314, wherein the control unit 320 is adapted to receive the
image signals from the image sensors 314 and determine a position
of the bright spot relative to the displaying surface 210 according
to the image signals. In other words, in the present embodiment,
the control unit 320 is adapted to determine a position of the
touch object 50 relative to the displaying surface 210 according to
the light beam 313 reflected by the touch object 50 and sensed by
the first image sensor 314a and the second image sensor 314b. In
the present embodiment, the light sources 312, for example, are
light emitting diodes (LEDs), laser diodes, or other light emitting
devices, and the light beam 313, for example, is an infrared ray
(IR), a visible light beam, a laser beam, or an electromagnetic
radiating wave having wavelengths in a suitable range. However, the
present invention is not limited thereto. Furthermore, the touch
object 50, for example, is a user's finger or a tip of a touch
pen.
[0051] In the present embodiment, the control unit 320 includes at
least two signal processors 318 and a back-end processor 319. In
FIG. 1A, the at least two signal processors 318, for example, are
two signal processors 318a and 318b. The signal processors 318 are
electrically connected to the image sensors 314 of the touch units
310 respectively. That is, the signal processors 318a and 318b are
electrically connected to the first image sensor 314a and the
second image sensor 314b respectively. Each of the signal
processors 318 is adapted to determine the position of the bright
spot according to the image sensed by the corresponding image
sensor 314 and generate a one-dimensional coordinate signal. The
one-dimensional coordinate signal, for example, is an incident
angle of the light beam 313 reflected by the touch object 50 and
entering the image sensor 314. The back-end processor 319 is
electrically connected to the signal processors 318, wherein the
back-end processor 319 is adapted to receive the one-dimensional
coordinate signals generated by the signal processors 318 and
determine the position of the bright spot relative to the
displaying surface 210 according to the one-dimensional coordinate
signals. Specifically, the back-end processor 319 calculates the
position of the bright spot relative to the displaying surface 210
according to two incident angles of the light beam 313 respectively
entering the two different image sensors 314. In the present
embodiment, after calculating the position of the bright spot
relative to the displaying surface 210, the back-end processor 319
transmits a position signal to the operating platform 90 connected
with the back-end processor 319, so that the operating platform 90
determines the position of the touch object relative to a frame
displayed on the displaying surface 210. Accordingly, the touch
function is provided. In the present embodiment, the operating
platform 90, for example, is a computer. However, in other
embodiments, the operating platform 90 may be a cell phone, a
personal digital assistant (PDA), a digital camera, or another
suitable electrical control system or electrical device.
[0052] It should be noted that, the present invention is not
limited to the arrangement of the signal processors 318 and the
back-end processor 319, such as the disposition and the assembly.
For example, in the present embodiment, the signal processors 318
are assembled in the touch unit 310 and electrically connected with
the back-end processor 319 through transmission lines. However, in
other embodiments, the signal processors 318 and the back-end
processor 319 may be integrated in the same chip. Alternatively,
one of the signal processors 318a and 318b and the back-end
processor 319 may be integrated in the same chip, and the other
thereof may be electrically connected with the chip through the
transmission lines. Alternatively, the back-end processor 319 may
be integrated in the processor of the operating platform 90. That
is, the operation of the back-end processor 319 is provided by
using the program and the processor of the operating platform.
[0053] In the present embodiment, the light sources 312 include at
least one first light source 312a, e.g. two first light sources
312a shown in FIG. 1A, and at least one second light source 312b,
e.g. two second light sources 312b shown in FIG. 1A, which are
respectively disposed at a third position and a fourth position,
e.g. the positions shown in FIG. 1A, beside the displaying surface.
In the present embodiment, the third position and the fourth
position are respectively located at two neighboring corners of the
displaying surface 210. The first position and the third position
are respectively located beside a same corner of the displaying
surface 210, and the second position and the fourth position are
respectively located beside a same corner of the displaying surface
210. Furthermore, the first position and the second position may be
respectively located at two neighboring corners of the displaying
surface 210. In other words, in the present embodiment, the first
light source 312a and the first image sensor 314a are combined in
one of the two touch units 310, and the second light source 312b
and the second image sensor 314b are combined in the other of the
two touch unit 310. Moreover, the two touch units 310 are
respectively located at two neighboring corners of the displaying
surface 210.
[0054] FIG. 2A is a driving period distribution of the control unit
in FIG. 1A. Referring to FIG. 1A through FIG. 1C and FIG. 2A, in
the present embodiment, the control unit 320 is adapted to drive
the light sources 312 of the touch units 310 by turns.
Specifically, the control unit is adapted to continuously control
the first light source 312a and the second light source 312b in a
plurality of continuous unit times T. Each of the unit times T
includes a first sub-unit time U1 and a second sub-unit time U2.
The control unit 320 is adapted to control the first light source
312a to stay at an ON state and the second light source 312b to
stay at an OFF state in the first sub-unit time U1. In other words,
as shown in FIG. 2A, the first light source 312a is driven by a
current, and a current passing through the second light source 312b
is controlled to be substantially equal to zero in the first
sub-unit time U1. The control unit 320 is adapted to control the
first light source 312a to stay at the OFF state and the second
light source 312b to stay at the ON state in the second sub-unit
time U2. In other words, as shown in FIG. 2A, the current passing
through the first light source 312a is controlled to be
substantially equal to zero, and the second light source 312b is
driven by the current in the second sub-unit time U2. It should be
noted that, the waveform of the driving currents is a square wave
as an example. However, in other embodiments, the waveform of the
driving currents may be a sine wave, a triangle wave, a circle
wave, a wave having a horizontally asymmetric waveform, a wave
having a regular waveform, or a wave having an irregular
waveform.
[0055] In the present embodiment, the control unit 320 is adapted
to control the first image sensor 314a to stay at the ON state and
the second image sensor 314b to stay at the OFF state in the first
sub-unit time U1, as shown in FIG. 2A. Moreover, the control unit
320 is adapted to control the first image sensor 314a to stay at
the OFF state and the second image sensor 314b to stay at the ON
state in the second sub-unit time U2. It should be noted that, the
ON state and the OFF state at which the image sensors are
respectively mean that the image sensors are substantially turned
on and that the image sensors are substantially turned off.
Alternatively, they may respectively mean that the data is
available and that the data is unavailable.
[0056] As a result, when the first image sensor 314a is turned on
in the first sub-unit time U1, the first image sensor 314a senses
the reflected light beam 313 emitted by the first light source 312a
instead of the light beam 313 emitted by the second light source
312b which directly enters the first image sensor 314a or is
reflected and transmitted to the first image sensor 314a.
Accordingly, the first image sensor 314a is not interfered with the
second light source 312b. On the contrary, when the second image
sensor 314b is turned on in the second sub-unit time U2, the second
image sensor 314b senses the reflected light beam 313 emitted by
the second light source 312b instead of the light beam 313 emitted
by the first light source 312a which directly enters the second
image sensor 314b or is reflected and transmitted to the second
image sensor 314b. Accordingly, the second image sensor 314b is not
interfered with the first light source 312a. Since the image sensor
314 is not interfered with the light source 312 of the different
touch unit 310, the touch screen 100 and the touch module 300
thereof have low failure rate in the present embodiment.
[0057] It should be noted that, the arrangement and the periods of
the first sub-unit time U1 and the second sub-unit time U2 in the
unit time T do not limit the present invention. For example, in
other embodiments, the second sub-unit time U2 may be arranged
prior to the first sub-unit time U1. Alternatively, the first
sub-unit time U1 and the second sub-unit time U2 may be adjacent to
each other or not, and the first sub-unit time U1 and the second
sub-unit time U2 may not fully fill the unit time T. Moreover, it
does not limit the present invention that the first image sensor
314a and the second image sensor 314b are alternatively turned on.
In other embodiments, the first image sensor 314a and the second
image sensor 314b may be both maintained at the ON state all the
time in each of the unit times T. The control unit 320, for
example, is adapted to obtain a sensed result of the first image
sensor 314a to analyze in the first sub-unit time U1. That is, the
data of the first image sensor 314a is available, but the data of
the second image sensor 314b is unavailable in the first sub-unit
time U1. Meanwhile, the control unit 320 is adapted to obtain a
sensed result of the second image sensor 314b to analyze in the
second sub-unit time U2. That is, the data of the second image
sensor 314b is available in the second sub-unit time U2, but the
data of the first image sensor 314a is unavailable. As a result,
even if the image sensors 314 are not turned off at the right
moment, a determined result of the control unit 320 for the
position of the touch object is not affected.
[0058] In the touch screen 100 and the touch module 300 of the
present embodiment, the image sensors 314 are used capture the
bright spot, i.e. the light beam reflected by the touch object 50.
Compared with the touch module in which capturing the dark spot,
i.e. the light shading spot, is adopted, and the good back light
source is formed by disposing the reflecting bars and the light
emitting bars on the edges of the displaying surface, the
reflecting bars and the light emitting bars are not required by the
touch screen 100 and the touch module 300 in the embodiment, so
that the structures thereof are simpler. Accordingly, it can reduce
cost of the touch screen 100 and the touch module 300, and the
touch screen 100 is beautiful. Moreover, the touch module 300 of
the present embodiment is disposed beside the displaying surface
210, so that the light beams emitted from the displaying surface
210 are not screened. Compared with the displaying surface in the
related art which is covered by a touch film, so that optical
quality of the display using the same is affected, the touch module
300 of the present embodiment does not affect optical quality of
the display 200. Accordingly, the touch screen 100 of the present
embodiment has better optical quality.
[0059] Furthermore, in the present embodiment, the control unit 320
is adapted to control the image sensor 314 to repeatedly capture
the bright spot in the sensing space S and determine a position
change of the bright spot according thereto. As a result, the
operating platform 90 can obtain the movement of the touch object
50, so that a drag function similar to a mouse is provided.
[0060] It should be noted that, it does not limit the present
invention that the touch module 300 has the light sources 312. In
other embodiments, the touch module 300 may not have the light
sources 312, and the light beam 313 is provided by other light
sources, such as the light sources or the reflected light beams in
the environment.
[0061] FIG. 2B is a flowchart of a control method of the touch
module shown in FIG. 1A. Referring to FIG. 1A, FIG. 2A, and FIG.
2B, the touch module 300 shown in FIG. 1A is adapted to be
controlled by using the control method of the present embodiment,
and the control method is performed via the control unit 320. The
control method of the present embodiment includes following steps.
First of all, when at least one touch object 50 enters the sensing
space S, the first image sensor 314a and the second image sensor
314b are controlled to sense the light beam 313 reflected by the
touch object 50 in step S110. In the present embodiment, one touch
object 50 is exemplary. In the present embodiment, step S100
includes steps S112 and S114. In step S112, the first light source
312a is controlled to stay at the ON state, and the second light
source 312b is controlled to stay at the OFF state in the first
sub-unit time U1. In step S114, the first light source 312a is
controlled to stay at the OFF state, and the second light source
312b is controlled to stay at the ON state in the second sub-unit
time U2. In the present embodiment, after step S112, step S114 is
performed. In other embodiments, they may be changed in order.
[0062] In step S112, the control method of the present embodiment
further includes that the first image sensor 314a is controlled to
stay at the ON state and the second image sensor 314b is controlled
to stay at the OFF state. Moreover, in step S114, the control
method of the present embodiment further includes that the first
image sensor 314a is controlled to stay at the OFF state and the
second image sensor 314b is controlled to stay at the ON state.
However, in other embodiments, the first image sensor 314a and the
second image sensor 314b may be maintained at the ON state all the
time in each of the unit times.
[0063] Next, in step S120, the position of the touch object 50
relative to the displaying surface 210 is determined according to
the light beam 313 reflected by the touch object 50 and sensed by
the first image sensor 314a and the second image sensor 314b.
[0064] Thereafter, steps S110 and S120 may be repeated, so that the
position change of the touch object 50 is sensed.
[0065] It is adopted in the control method of the present
embodiment to sense the bright spot, i.e. a reflex point of the
touch object 50. Compared with capturing the dark spot, i.e. the
light shading spot, in the related art in which the reflecting bars
and the light emitting bars are required, the reflecting bars and
the light emitting bars are not required in the control method of
the present embodiment. Accordingly, it can simplify the structure
of the touch module 300. Moreover, since the light sources 312 are
alternatively turned on in the control method of the present
embodiment, the image sensor 314 is not interfered with the light
source 312 of the different touch unit 310, so that lower failure
rate is provided in the control method of the present
embodiment.
[0066] FIG. 3A is a front view of a touch screen and an operating
platform according to another embodiment of the present invention.
FIG. 3B is a schematic cross-sectional view of the touch screen in
FIG. 3A along line II-II. FIG. 4A is a driving period distribution
of the control unit in FIG. 3A. Referring to FIG. 3A, FIG. 3B, and
FIG. 4A, the touch screen 101 of the present embodiment is similar
to the said touch screen 100 (as illustrated in FIG. 1A and FIG.
1B), and the difference between these two touch screens is
described as below. In the touch screen 100 shown in FIG. 1B, the
displaying surface 210 is recessed with respect to a frame 220 of
the display 200. However, in touch screen 101 of the present
embodiment, surfaces of the displaying surface 210 and the frame
220 are substantially on the same plane. When the display 201 is
used, an environment light beam 72 emitted by an environment light
source 70, such as an emitted light beam or a reflected light beam,
easily interferes with the sensing results of the image sensors
314. In order to solve the issue, each of the unit times T' further
includes a third sub-unit time U3 in the present embodiment. In the
third sub-unit time U3, the control unit 320 is adapted to control
the first light source 312a and the second light source 312b to
stay at the OFF state. The control unit 320 is adapted to subtract
an image brightness sensed by the first image sensor 314a in the
third sub-unit time U3 of each of the unit times T' from an image
brightness sensed by the first image sensor 314a in the first
sub-unit time U1 of the corresponding unit time T' to obtain a
first touch image. The control unit 320 is adapted to subtract an
image brightness sensed by the second image sensor 314b in the
third sub-unit time U3 of each of the unit times T' from an image
brightness sensed by the second image sensor 314b in the second
sub-unit time U2 of the corresponding unit time T' to obtain a
second touch image. The control unit 320 determines the position of
the touch object 50 relative to the displaying surface 210
according to the first touch image and the second touch image. In
other words, in the third sub-unit time U3, the first image sensor
314a and the second image sensor 314b both stay at the ON state.
However, in other embodiments, the third sub-unit time U3 may be
divided into two different sub-unit times, and the first image
sensor 314a and the second image sensor 314b are respectively
turned on during the two different sub-unit times.
[0067] Through the said subtraction of the two image brightness
performed by the control unit 320, the image due to the environment
light beam 72 is eliminated, so that the exact position of the
touch object 50 is obtained without being interfered with the
environment light beam 72. The said touch module 300 may be applied
to a projection screen. Since the projection screen has no frame,
it is easily interfered with the environment light beam 72.
Accordingly, the said issues can be effectively solved in the touch
module 300 of the present embodiment. Furthermore, the touch module
300 of the present embodiment may be applied to the touch screen
100 shown in FIG. 1A to solve the interference with the environment
light beam relatively tilting to the displaying surface 210.
[0068] It should be noted that, in other embodiments, the order of
the first sub-unit time U1, the second sub-unit time U2, and the
third sub-unit time U3 may be changed to another possible
order.
[0069] FIG. 4B is a flowchart of a control method of the touch
module shown in FIG. 3A. Referring to FIG. 3A, FIG. 4A, and FIG.
4B, the control method of the present embodiment is similar to the
said control method as illustrated in FIG. 2B, and the difference
between these two control methods is described as below. In the
present embodiment, step S110' further includes step S116. In step
S116, the first light source 312a and the second light source 312b
are controlled to stay at the OFF state in the third sub-unit time
U3. Moreover, in the present embodiment, step S120' includes steps
S122 and S124. In step S122, the image brightness sensed by the
first image sensor 314a in the third sub-unit time U3 is subtracted
from the image brightness sensed by the first image sensor 314a in
the first sub-unit time U1 to obtain a first touch image.
Furthermore, the image brightness sensed by the second image sensor
314b in the third sub-unit time U3 is subtracted from the image
brightness sensed by the second image sensor 314b in the second
sub-unit time U2 to obtain a second touch image. Moreover, after
step S122, step S124 is performed. the position of the touch object
50 relative to the displaying surface is determined according to
the first touch image and the second touch image.
[0070] Through the said subtraction of the two image brightness,
the image due to the environment light beam 72 is eliminated, so
that the exact position of the touch object 50 is obtained without
being interfered with the environment light beam 72. The said
control method may be applied to the projection screen. Since the
projection screen has no frame, it is easily interfered with the
environment light beam 72. Accordingly, the said issues can be
effectively solved in the control method of the present embodiment.
Furthermore, the control method of the present embodiment may be
applied to the touch screen 100 shown in FIG. 1A to solve the
interference with the environment light beam relatively tilting to
the displaying surface 210.
[0071] FIG. 5A is a front view of a touch screen and an operating
platform according to another embodiment of the present invention.
FIG. 5B is a schematic cross-sectional view of the touch screen in
FIG. 5A along line III-III. Referring to FIG. 5A and FIG. 5B, the
touch screen 102 of the present embodiment is similar to the said
touch screen 100 (as illustrated in FIG. 1A and FIG. 1B), and the
difference between these two touch screens is described as below.
In the present embodiment, the touch module 302 further includes at
least one absorbing bar 330 which is disposed on at least one edge
of the displaying surface 210. For example, the number of the
absorbing bars 330 is three, and they are respectively disposed on
the three edges of the displaying surface 210. The absorbing bars
330 can absorb the light beam 313 from the light source 212 which
should illuminate on the frame 220. Accordingly, it is avoided that
the light beam 313 reflected by the frame 220 interferes with the
image sensor 314 of the different touch unit 310. In another
embodiment, the absorbing bars 330 may be replaced with
light-turning bars 330a, as shown in FIG. 5C. The light-turning
bars 330a are adapted to reflect the light beam 313 to a direction
far away from the displaying surface 210. Accordingly, it is
avoided that the light beam 313 reflected by the frame 220
interferes with the image sensor 314 of the different touch unit
310.
[0072] FIG. 6A is a front view of a touch screen and an operating
platform according to another embodiment of the present invention.
FIG. 6B is a schematic cross-sectional view of the touch screen in
FIG. 6A along line IV-IV. Referring to FIG. 6A and FIG. 6B, the
touch screen 103 of the present embodiment is similar to the said
touch screen 102 (as illustrated in FIG. 5A and FIG. 5B), and the
difference between these two touch screens is described as below.
The display 200 of the touch screen 102 is replaced with the
display 201 in FIG. 3B, so that the touch screen 103 is provided in
the present invention. Moreover, the absorbing bars 330 of the
touch module 302 shown in FIG. 5A and FIG. 5B are disposed in a
recess 222 surrounded by the frame 220. However, the absorbing bars
330 of the touch module 303 of the present embodiment are disposed
on a front surface 224 of the frame 220. The absorbing bars 330 can
absorb the environment light beam parallel to the displaying
surface 210, so that the sensing result of the image sensor 314
Accordingly, it is avoided that the environment light beam
interferes with the sensing result of the image sensor 314.
[0073] FIG. 7 is a front view of a touch screen and an operating
platform according to another embodiment of the present invention.
FIG. 8A is a driving period distribution of the control unit in
FIG. 7. Referring to FIG. 7 and FIG. 8A, the touch screen 104 of
the present embodiment is similar to the said touch screen 100 in
FIG. 1A, and the difference between these two touch screens is
described as below. In the present embodiment, the touch screen 104
has two additional touch modules 310. Specifically, the touch
module 310 further includes a third image sensor 314c and a fourth
image sensor 314d which are respectively disposed at a fifth
position and a sixth position beside the displaying surface 210,
such as the positions shown in FIG. 7. In the present embodiment,
sensing surfaces 315 of the third image sensor 314c and the fourth
image sensor 314d face to the sensing space S. In the present
embodiment, the four touch modules 310 are respectively disposed at
four corners of the displaying surface 210. However, in other
embodiments, the touch modules 310 may be respectively disposed at
other suitable positions.
[0074] The light sources 312 further include at least one third
light source 312c, e.g. two third light sources 312c shown in FIG.
7, and at least one fourth light source 312d, e.g. two fourth light
sources 312d shown in FIG. 7, which are respectively disposed at a
seventh position and an eighth position, e.g. the positions shown
in FIG. 7, beside the displaying surface 210. Each of the unit
times T'' further includes a fourth sub-unit time U4 and a fifth
sub-unit time U5. The control unit 324 is adapted to further
control the third light source 312c and the fourth light source
312d to stay at the OFF state in the first sub-unit time U1. The
control unit 324 is adapted to further control the third light
source 312c and the fourth light source 312d to stay at the OFF
state in the second sub-unit time U2. The control unit 324 is
adapted to control the third light source 312c to stay at the ON
state and the first light source 312a, the second light source
312b, and the fourth light source 312d to stay at the OFF state in
the fourth sub-unit time U4. The control unit 324 is adapted to
control the fourth light source 312d to stay at the ON state and
the first light source 312a, the second light source 312b, and the
third light source 312c to stay at the OFF state in the fifth
sub-unit time U5. In the present embodiment, the first image sensor
314a, the second image sensor 314b, the third image sensor 314c,
and the fourth image sensor 314d are respectively turned on and
sense the images during the first sub-unit time U1, the second
sub-unit time U2, the third sub-unit time U3, and the fourth
sub-unit time U4. However, in other embodiments, the first image
sensor 314a, the second image sensor 314b, the third image sensor
314c, and the fourth image sensor 314d may be maintained at the ON
state all the time in each of the unit times T''.
[0075] In the present embodiment, the number of the touch objects
50, for example, is two. That is, the touch object 50a and the
touch object 50b are exemplary herein. When the touch objects 50
are simultaneously located in the sensing space S in at least one
of the unit times T'', the touch images sensed by the first image
sensor 314a, the second image sensor 314b, the third image sensor
314c, and the fourth image sensor 314d each have at least one
reflex point in the unit times T''. For example, since the first
image sensor 314a, the touch object 50b, the touch object 50a, and
the fourth image sensor 314d are arranged in the same straight
line, the first image sensor 314a simply senses the reflex point
formed by the touch object 50b instead of the reflex point formed
by the touch object 50a. On the contrary, the fourth image sensor
314d simply senses the reflex point formed by the touch object 50a
instead of the reflex point formed by the touch object 50b.
Accordingly, each of the first image sensor 314a and the fourth
image sensor 314d simply senses one reflex point. Furthermore, the
touch images sensed by at least two of the first image sensor 314a,
the second image sensor 314b, the third image sensor 314c, and the
fourth image sensor 314d each have two reflex points For example,
the second image sensor 314b and the third image sensor 314c each
sense two reflex points in the present embodiment. As a result, two
of the four one-dimensional coordinate signals respectively
outputted by the first image sensor 314a, the second image sensor
314b, the third image sensor 314c, and the fourth image sensor 314d
respectively include two one-dimensional coordinates, and the other
two thereof respectively include an one-dimensional coordinate.
Accordingly, more than two positions of the touch objects 50 are
obtained but not consistent with the practical situation.
Generally, the four one-dimensional coordinate signals may
respectively include two one-dimensional coordinates, so that a lot
of positions inconsistent with the practical situation are
obtained.
[0076] In order to solve the said issue, the control unit 324 is
adapted to compare the positions of the reflex points in the touch
images to eliminate the positions of the touch objects 50 relative
to the displaying surface 210 which do not exist and determine the
positions of the touch objects 50 relative to the displaying
surface 210. In other words, after receiving the four
one-dimensional coordinate signals, the control unit 324 calculates
the data of the plurality of the positions according thereto. Next,
the conjunction of the data is viewed as the practical position,
and the others are eliminated. As a result, the touch screen 104
and the touch module 304 of the present embodiment can exactly
determine the positions of the two touch objects 50. Accordingly,
multi-touch is provided. Moreover, along with the increase of touch
points, e.g. more than three touch points, more touch units 310 are
adopted in other embodiments of the present invention, so that the
positions of the touch points can be exactly determined.
[0077] It should be noted that, the touch screen 104 and the touch
module 304 of the present embodiment are not only adapted to
determine the positions of the two touch objects 50. If only one
touch object 50 enters the sensing space S, the control unit 324
simply calculates the data of one position according to the four
one-dimensional coordinate signals outputted by the four image
sensors 314. Accordingly, it is not required to eliminate the data
of the position inconsistent with the practical situation for the
control unit. Furthermore, in another embodiment, the four touch
units 310 may be grouped into two sets. For example, the upper two
touch units are grouped into one set in FIG. 7, and the lower two
touch units are grouped into the other set in FIG. 7. Moreover, in
the first sub-unit time U1, the light sources 312a and 312b of the
upper two touch units 310 are simultaneously turned on, but the
light sources 312c and 312d of the lower two touch units 310 are
simultaneously turned off. Next, in the second sub-unit time U2,
the light sources 312c and 312d of the lower two touch units 310
are simultaneously turned on, but the light sources 312a and 312b
of the upper two touch units 310 are simultaneously turned off. By
arranging the positions of the light sources 312, the light beams
313 emitted by the light sources 312a and 312b of the upper two
touch units 310 may not or little directly enter the image sensors
314b and 314a respectively, and the light beams 313 emitted by the
light sources 312c and 312d of the lower two touch units 310 may
not or little directly enter the image sensors 314d and 314c
respectively, either. Accordingly, the exact determination for the
positions of the touch objects 50 is also provided.
[0078] FIG. 8B is a flowchart of a control method of the touch
module shown in FIG. 7. Referring to FIG. 7, FIG. 8A, and FIG. 8B,
the control method of the present embodiment is similar to the said
control method as illustrated in FIG. 2B, and the difference
between these two control methods is described as below. In step
S112'' of step S110'', the third light source 312c and the fourth
light source 312d are further controlled to stay at the OFF state
in the first sub-unit time U1. In step S114'', the third light
source 312c and the fourth light source 312d are further controlled
to stay at the OFF state in the second sub-unit time U2. Moreover,
step S110'' further includes steps S116'' and S118''. In step
S116'', the third light source 312c is controlled to stay at the ON
state and the first light source 312a, the second light source
312b, and the fourth light source 312d are controlled to stay at
the OFF state in the fourth sub-unit time U4. In step S118'', the
fourth light source 312d is controlled to stay at the ON state and
the first light source 312a, the second light source 312b, and the
third light source 312d are controlled to stay at the OFF state in
the fifth sub-unit time U5. In the present embodiment, the number
of the touch objects, for example, is two. When the touch objects
50 are simultaneously located in the sensing space S in at least
one of the unit times T'', the touch images sensed by the first
image sensor 314a, the second image sensor 314b, the third image
sensor 314c, and the fourth image sensor 314d respectively have at
least one reflex point, and at least two of the touch images sensed
by the first image sensor 314a, the second image sensor 314b, the
third image sensor 314c, and the fourth image sensor 314d
respectively have two reflex points in the unit times T''.
Accordingly, in the present embodiment, step S120'' further
includes a step of comparing positions of the reflex points in the
touch images to eliminate the positions of the touch objects 50
relative to the displaying surface 210 which do not exist and
determine the positions of the touch objects 50 relative to the
displaying surface 210. As a result, the positions of the two touch
objects 50 can be exactly determined in the control method of the
present embodiment.
[0079] The number of the adopted touch units 310 is two or four,
but the present invention is not limited thereto. In other
embodiment, another number of the touch units 310 is adopted.
Another embodiment is given for illustration below.
[0080] FIG. 9 is a front view of a touch screen and an operating
platform according to another embodiment of the present invention.
Referring to FIG. 9, the touch screen 105 of the present embodiment
is similar to the said touch screen 104 in FIG. 7, and the
difference between these two touch screens is described as below.
In the present embodiment, the touch modules 105 simply have three
touch units 310, and one of the three touch units 310 is disposed
at the bottom edge of the displaying surface 210. The control unit
325 and the control method of the present embodiment is similar to
the said embodiment as illustrated in FIG. 7, FIG. 8A, and FIG. 8B.
For example, the control unit 325 drives the light sources 312 of
the three touch units 310 by turns. Moreover, the control unit 325
compares the bright spots captured by the image sensors 314 of the
three touch units 310 to eliminate the data of the incorrect
positions. Accordingly, the exact positions of the two touch
objects 50 are obtained. Furthermore, three touch units 310 are
adopted in the present embodiment, so that it enhances accuracy of
determining the position of the single touch object 50.
[0081] To sum up, in the touch screen, the touch module, and a
control method of the touch module of the embodiments consistent
with the present invention, the image sensor is used to capture the
bright spot, i.e. the light beam reflected by the touch object.
Compared with the touch module in which capturing the dark spot,
i.e. the light shading spot, is adopted, and the good back light
source is formed by disposing the reflecting bars and the light
emitting bars on the edges of the displaying surface, the
reflecting bars and the light emitting bars are not required by the
touch screen and the touch module of the embodiments consistent
with the present invention, so that the structures thereof are
simpler. Accordingly, it can reduce cost of the touch screen and
the touch module, and the touch screen is beautiful.
[0082] Moreover, the light sources are controlled to stay at the ON
state by turns in the touch module, the touch screen, and the
control method thereof in the embodiments consistent with the
present invention. Accordingly, it is avoided that the image
sensors are interfered with light beams emitted by unnecessary
light sources. Therefore, the touch module, the touch screen, and
the control method thereof in the embodiments consistent with the
present invention have low failure rate.
[0083] Although the present invention has been described with
reference to the above embodiments, it is apparent to one of the
ordinary skill in the art that modifications to the described
embodiments may be made without departing from the spirit of the
invention. Accordingly, the scope of the invention will be defined
by the attached claims not by the above detailed descriptions.
* * * * *